Yarn winding



Sept. 25, 1956 H. HAL'KYARD Em. 2,764,368

YARN WINDING Filed Oct. 27, 1953 ggg l 1 Unite States Patent O Derby,England, assignors to BritishV Celanese Limited,l

a corporation of Great Britain Application October 27, 1953, Serial No.388,514

Claims priority, application Great` Britain October31., 1952 4 Claims.(Cl. 242-459) This invention relates to yarn winding and particularlytothe winding of cones of yarn, i. e. packages ofyarn in which the yarnmass is cross-wound on a. taperedslpport or tube and presents apart-conical outer surface and two. end surfaces, each layer of yarn(consisting of a few turns round the package) extending substantiallyfrom one end surface to the other.

Accordingto the present invention, a method of winding cones of yarncomprises effecting each traverse of the yarn from the small to thelarge end ofthe. cone in a shorter time than the preceding or succeedingtraverse from the large to the small end. This can be brought aboutwhen, as is usual, a constantly rotated cam' or the like is provided toeffect thev traversing, by making the part or parts of the cam surfacesby which the traverse from the small to the large end of the cone iseffected to subtend a smaller angle at the axis of the cam than the partor parts by which the traverse from the large to the small end iseffected. Thus, when the cam is such as to effect one completeto-and-fro traverse cycle for each revolution, the part effecting thetraverse from the small to the large end of the cone may extend ratherless than 180 round the axis of the cam, and the remaining part rathermore than 180.

The principal advantage of the invention is that it facilitates theselection of the Wind ratio employed in winding a cone, i. e. the numberof revolutions of the cone occurring during each traverse from one endof the cone to the other. This ratio depends upon the angular speedratio between the cam and the winding spindle on which the cone iscarried during winding. It is found that if the wind ratio is too small(e. g. below 2.5) the yarn at each end of the package, where it turnsfrom one traverse Ainto the next, is apt to slip back from the endsurface of the package to a greater or less degree, giving rise toirregularities at the end of the package which manifest themselves whenthe package is unwound by irregular yarn tensions or even by jamming andbreaking of the yarn. This difficulty, which chiefly occurs at theinnermost layers of the yarn on the cone, can be overcome by increasingthe wind ratio. However, if too high a wind ratio is employed (e. g.above 2.75) the end surfaces of the package and the outer surface nearthe ends are apt to bulge, apparently due to the greater pressure of theyarn and to a reduced resistance to movement of the yarn, under thatpressure, axially of the package. Bulging of this kind gives rise todiliiculties in unwinding the package and, when it occurs near the endsof the outer surface of the package, causes difficulty in winding also,the yarn guide by which the yarn is led to the package being apt tostrike the bulge in the course of traversing and to damage, and even toeut through the yarn therein. It has been found that, especially withartificial continuous filament yarns which are of a smooth and slipperycharacter, these diliiculties may overlap, e. g. at a wind ratio in theneighbourhood of 2.75, so that the wind ratio cannot be made high enoughto overcome the first difficulty without running into the second. It has2,764,368 Patented Sept.' 25,1956

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further been found, however, that by thev use of the present invention awind ratio can be chosen (different, in accordance with the inventionfor the different direc1 tions of traverse) by which both difculties areovercome'.

As already indicated,` the inventionis of particularadvantage in thevwinding of cone's ofl smooth and, SlipperyV yarn, particularlyartificial continuousflament yarn, e. g. Continuousfilament celluloseacetate yarn. produced by the dry or evaporative spinning method.v Thecones of., yarn produced in accordance` with the invention -arecharacterised in that eachA layerof yarn therein extending, (in theorder of winding) from the lsmall to the, large end of the cone has asmaller angle of wrap round the axis of the package (and consequently a,largerhelix' angle)- than the adjoining layers of yarn extending in theopposite direction. The invention includesv within its scope, inaddition to the methody of cone windingv defined above, cones, of yarnhaving this characteristi fea.- ture, and the traverse, cams (and,cone-winding IIIaallilttsV incorporating them.) designed to produce suchpackages.

By way of example, one form of traverse cam in accordance with` theinvention, and a cone-winding machine incorporating such cams, togetherwith the way in which; it is operated to carry out the method' of the.linvention,

, will new be. described in greater detail with reference toV the:accompanying drawing, inV which:

Figure. l is a diagrammatic rear elevation of. a4 single unit, orspindle, in a cone-winding machine having a series of such unitsarranged in line, and

Figure 2 is an end-diagram of the cam in Figure l, showing its angularproportions.

The cam, of which one is provided for each spindle, is indicated at 3and comprises a channel-sectioned member having two parts 4, 5 ofhelical form, extending in opposite directions round the surface of animaginary cylinder (represented at 6 in Figure 2) and joined at theirends at 7, 8 to form a continuous cam surface, the channel sectionopening outwards with reference to the surface 6 to receive a cam-bowl 9or like cam follower. The channel-sectioned member 3 is supported by aspider 10 from a central hub 11 which is coaxial with the surface of theimaginary cylinder 6 and is mounted on a cam shaft 12 by which the camis rotated. The diameter of the cylinder 6 is 6, the axial length of thegroove or channel is 6" and its width The two parts 4, 5 of the cam 3,while equal in axial extent, do not cover equal angles of round the axisof the cam. The part 4 covers an angle of 198 round the shaft 12 whilethe part 5, which is therefore of greater helical pitch than the part 4,covers an angle of 162.

The shaft 12 is connected through suitable gearing 14 to a windingspindle 15 on which is mounted a'tapered tube 16 forming the basis ofthe cone 17 to be wound. The spindle 15 is driven from a Ishaft 18,common to all the spindles of the machine, by means of skew gears 19.Yarn, indicated at 13, is guided to the tube 16 by means of a yarn guide20 mounted on a rod indicated at 21 and extending parallel to thesurface of the tapered tube 16 and that of the cone 17. The rod 21 ismounted in slides 22 so that it can move in the direction of its ownlength and carry the traverse guide 20 to-and-fro along the length ofthe tapered tube 16. The slides 22 are mounted on arms 23 which arepivoted on the cam shaft 12 and biassed by a counterweight 24 so thatthe traverse guide rests in contact with the tube 16 or with the surfaceof the yarn already wound thereon. Carried by the rod is the cam-bowl orfollower 9 which engages the groove round the periphery of the cam 3 sothat the rod 21 moves to-and-fro by rotation of the cam 3. The cam 3 isrotated in such a direction that the portion 4 thereof which extends forthe greater angle round the 3 shaft 12 of the cam drives the traverseguide 20 from the base 25 towards the tip 26 of the tapered tube 16,while the remaining part 5 ofthe cam drives the traverse guide 20 in thereverse direction.

The Cam shaft 12 and the spindle 1S are geared t0 give a speed ratiobetween'themof about 5.48:l (exact whole-number ratios, or simplefractions are to be avoided). The average wind-ratio as defined above istherefore 2.74. Owing to the inequality of the angles covered by the twoparts 4, 5 of the cam, however, the wind-ratio of the travers'e from thebase 25 to the tip 26 of the cone is 3.044, while that from the tip 2.6to the base 25 is 2.436. In spite of the low wind-ratio from tip to baseof the cone, cones with good regularity in the early layers of yarn canbe obtained while, in spite of the high wind-ratio from base to tip, thecones are of vgood external shape and free from undue bulging.

Having described our invention, what we desire to secure by LettersPatent is:

1. A method of winding artificial continuous filament yarn intocross-wound cones of yarn presenting two end surfaces and having eachlayer of yarn therein extending substantially from one end surface tothe other, said method comprising effecting each traverse of the yarnfrom the small to the large end of the cone in a time that is shorter byup to 25% than that taken by the preceding or succeeding traverse fromthe large to the small end of the cone.

2. A method of winding artificial continuous filament yarn intocross-wound cones of yarn presenting two end surfaces and having eachlayer of yarn therein extending substantially from one end surface tothe other, said method comprising effecting each traverse of the yarnfrom the large to the small end of the cone in a number of revolutionsof the cone more than 2.75, and effecting each traverse of the yarn fromthe small to the large end of the cone in a number of revolutions lessthan said number of revolutions by up to 25% and less than 2.75.

3. Cross-wound cones of articial continuous filament yarn in which eachlayer of yarn extending from one end surface of the cone to the otherend surface and in which each layer extending, in the order of winding,from the small to the large end of the cone has an angle of wrap roundthe axis of the cone that is smaller, by up to 25%, than the angle ofwrap of the adjoining layers of yarn, extending from the large to thesmall end of the cone.

4. Cross-wound cones of artificial continuous filament yarn in whicheach layer of yarn extending from one end surface of the cone to theother end surface and in which each layer extending, in the order ofwinding, from the large to the small end of the cone has an angle ofwrap round the axis of the cone greater than 2.75 turns, while eachadjoining layer of yarn, extending from the small to the large end ofthe cone has an angle of Wrap that is smaller than said angle by up to25% and is smaller than 2.75 turns.

References Cited in the le of this patent UNITED STATES PATENTS1,647,535 McKean Nov. l, 1927 FOREIGN PATENTS 426,380 Germany Mar. l0,1926 341,118 Great Britain Ian. 15, 1931

